[Breast cancer screening in Japan--present status and recent movement].

As the incidence of breast cancer and deaths from breast cancer have been increasing, the Ministry of Public Welfare and Labor has been promoting breast cancer screening. Mammography screening began in fiscal year 2000 for those women 50 years of age or over, but attendance has not been increasing. This year (2004), the Ministry determined that mammography would be applicable to those 40 years of age or over and that screening with palpation alone would be abolished. To determine the effectiveness of the measures, mammography equipment, technologists, and readers were calculated. If the attendance were 50% of the 35,497 thousand women in this biennial screening, 40 persons would be examined by one apparatus per day, and, as there are 200 working days in a year, 1,109 apparatus would be needed. In the same way, if a technologist can examine 5,000 women, and a doctor can read 10,000 cases a year, both are apparently deficient in some prefectures. The standards of quality control for digital mammography have been determined by the Japan Radiological Society, and a "step phantom for mammography" has been developed. Qualitative evaluation of hard-copy clinical images has also started. All of the standards are presented in "Mammography Guidelines, Second Edition," published by Igakushoin, Tokyo, Japan, 2004.